Electric hoisting mechanism.



S P I L L I H P B Tm ELECTRIC HOISTING MECHANISM.

APPLICATION FILED MAR.27,1905.

2 SHEETS-SHEET 1.

witnusay No. 800,241. PATENTED SEPT. 26, 1905. J. B. PHILLIPS. ELECTRIC HOISTING MECHANISM.

APPLIGATION FILED MAR.27,1905.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

ELECTRIC HOISTING MECHANISM.

Specification of Letters Patent.

Patented Sept. 26, 1905.

Application filed March 2'7, 1905. Serial No. 252,124.

To all whom, it may concern:

Be it known that I, JAMEs B. PHILLIPS, a citizen of the United States of America, and a resident of Portland, Cumberland county, State of Maine, have invented certain new and useful Improvements in Electric Hoisting Mechanism, of which the following is a specification.

My invention relates to hoisting machinery such as is used for unloading vessels, building construction, and the like, and relates particularly to that class in which the hoistingdrum is connected by a clutch with the main gear, which gear is operated by the main motor. The main gear is provided with an automatic brake by which it is held firmly when the weight has been lifted and after the power has-been shut ofi from the main motor and in lowering the hoisting-drum is moved longitudinally out of engagement with the clutch, and it is then free to turn and to allow the load to drop.

The object of my invention is to regulate the descent of the load and the rotation of the drum and to automatically check the drum and to provide such mechanism for this purpose as will permit the control of the hoist from a distance.

I illustrate my invention by means of the accompanying drawings, in which is shown an electrical hoist having an attachment constructed according to my invention; but it will be understood that the apparatus may be operated equally well by steam, compressed air, or other motor.

In the accompanying drawings, Figure 1 is a plan of so much of the electric hoist as is necessary to understand my invention, portions being in section. Fig. 2 is an end View. Fig. 3 is an elevation illustrating the construction of the automatic brake.

B indicates the position of the main motor. 6 is the gear or pinion thereon.

C is the main gear keyed to the shaft S.

D indicates the automatic brake, which is thrown on by the cutting 011 of the power of the main motor, and a is a wooden frictionclutch on the main gear. In Fig. 3 I have shown the construction of the automatic brake referred to. As herein shown, 1 is the friction-strap passing around the friction-pulley D and tightened by means of a lever S, which extends horizontally outward and has a pivoting-point t and another pivot 6 adjacent thereto and to which the strap '2' is connected. To the outer end of the arm S is connected a core P of the solenoid O by means of a link a. The solenoid is connected on the same circuit as the main motor, and when the current is on the core P is lifted, raising the outer end of the lever S and releasing the friction-strap 0*. When the current is shut off from the main motor and the solenoid, the weight of the core P presses down the lever S and sets the brake.

A is the hoisting-drum, the end of which is adapted to engage the friction a and when not engaged turns freely on the shaft passing through its axis. This shaft is journaled in the uprights 112 and w, and a is a spring for throwing the drum laterally along the shaft, and so disengaging it from the friction. The drum is thrown into engagement with the friction by means of the screw f, working in the nut a, secured in the upright a" and adapted to impinge against the pin in the end of the shaft S, which pin through a cross-key and collar (not shown) serves to force the drum longitudinally into contact with the clutch.

The parts so far described are old and well known features of electric hoisting mechanism and require no more detailed description.

Means operated by a weight or other equivalent mechanical means are provided for throwing the friction into engagement, and means operated by a suitable auxiliary motor are provided to counteract the operation of the weight, and to so release the friction. As here shown, the screw f is operated by the gear F and the weight it, with the cord 9, is so applied. as normally to force the drum into contact with the friction. The pinion c of the auxiliary motor E engages with the gear F. This auxiliary motor when thrown into action by the operator acts to counteract the weight It, and so disengages the drum from the friction a.

It is understood that other equivalent mechanism may be used in place of the gear F and pinion e and that the weight A may be replaced by a spring or other mechanical apparatus for setting the screw.

The operation of the apparatus is as follows: The tendency of the weight ll is to turn the gear and screw in such a direction as to set the drum A against the clutch a. WVhen the auxiliary motor E is started, it has sufficient strength to counteract the weight 71, and rotate the gear in a direction such that the drum is disengaged from the friction, allowing the drum to revolve freely as the load drops. When the motor is thrown out of action, the weight operates to return the gear to the normal position, again setting the drum against the friction. If the current is completely shut off from the motor, the full force of the weight will at once act on the gear, checking the drum instantly; but if the current on the motor is gradually shut off the weight will be gradually applied and the drum will be gradually forced against the friction. Thus by regulating the amount of current going to the auxiliary motor the descent of the load may be accurately gaged, and if anything happens that the current is cut off or the motor fails to work for any reason the weight is at once automatically applied and the drum is checked.

It will be understood that a suitable controller is supplied to govern the main and auxiliary motors, and this controller may be located at any convenient point to oversee the work. For instance, in unloading vessels it would be located on the landing-stage, while the hoist itself may be on the dock, and it is this fact that the controller may be located wherever required that makes this form of hoist of peculiar value in unloading, building work, and the like. Where other power is used in the auxiliary motor, the controller will be of suitable form.

I claimi 1. In a friction-drum hoist, the combination of means operated by a weight or other like mechanism for throwing the drum into engagement with the friction and means operated by a suitable auxiliary motor for disengaging said friction against the action of said weight.

2. In a friction-drum hoist, the combination of a screw for throwing the drum into engagement with the friction, a weight or other like mechanical means for operating said screw to engage the drum' and an auxiliary motor for operating said screw to disengage said drum against the action of said weight.

3. In an electric hoisting-machin e, the combination of a main gear having a clutch thereon, a main motor, for operating said gear, an automatic brake for holding said gear when the main current is shut off, a hoisting-drum mounted axially in line with the main gear and having alimitcd longitudinal motion with relation to said clutch, the end of said drum being adapted to engage said clutch, means operated by an auxiliary motor for throwing said drum out of engagement with said clutch to release said drum from said clutch and a weight and cord or other like automatic means for turning said gear against the action of said auxiliary motor to throw said drum into engagement with the clutch for the purpose of checking its rotation.

4. In an electric hoisting-machine, the combination of a main gear having a clutch thereon, a main motor for operating said gear, an automatic brake for holding said gear when the main current is shut ofi, a hoisting-drum mounted axially in line with the main gear and having a limited longitudinal motion, the end of said drum being adapted to engage said clutch, a screw for throwing said drum into engagement with said clutch, an auxiliary gear for operating said screw, an auxiliary motor for turning said auxiliary gear and screw to release said drum and a cord and weight or other like automatic means for turning the auxiliary gear and screw to throw the drum into engagement with the clutch for the purpose of checking the rotation.

Signed at Portland, Maine, this 15th day of March, 1905.

JAMES B. PHILLIPS. Witnesses:

S. W. BATES, C. M. GODFREY. 

